Justin Bieber is getting $3 million for a two-year deal with Proactiv, partly because, his manager says, "the kid uses it." But also because he's a music — not a TV or movie — star.

Bieber joins a long list of pop stars who have shilled for Proactiv, including Katy Perry, Avril Lavigne, Sean "Diddy" Combs, Jessica Simpson, Alicia Keys and Mandy Moore. As the Reuters story states: "No one is more willing to talk about acne than a musician."

So why does the company choose Billboard chart-toppers instead of Hollywood luminaries to hawk acne solution? Greg Renker, co-founder of Proactiv creator Guthy-Renker, tells Reuters: "I love Julia Roberts, but I've probably had 15 movie experiences with her in my lifetime… I've listened to [Perry's] 'California Gurls' every day since it was released. Consumers are connecting to musical talent multiple times a day in a way that is more than visceral." Also? Julia Roberts would probably say no.